a, $H^++OH^-\to H_2O$
b, $Cu(OH)_2+2H^+\to Cu^{2+}+2H_2O$
c, $Fe_2O_3+6H^+\to 2Fe^{3+}+3H_2O$
d, $CaCO_3+2H^+\to Ca^{2+}+CO_2+H_2O$
e, $Al(OH)_3+OH^-\to AlO_2^-+2H_2O$
f, $Cl^-+Ag^+\to AgCl$
i, $CH_3COO^-+H^+\to CH_3COOH$
j, $2H^++SO_3^{2-}\to SO_2+H_2O$
k, $HCO_3^-+H^+\to CO_2+H_2O$
